2 * linux/include/linux/cpufreq.h
4 * Copyright (C) 2001 Russell King
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
11 #ifndef _LINUX_CPUFREQ_H
12 #define _LINUX_CPUFREQ_H
14 #include <linux/clk.h>
15 #include <linux/cpumask.h>
16 #include <linux/completion.h>
17 #include <linux/kobject.h>
18 #include <linux/notifier.h>
19 #include <linux/spinlock.h>
20 #include <linux/sysfs.h>
22 /*********************************************************************
24 *********************************************************************/
26 * Frequency values here are CPU kHz
28 * Maximum transition latency is in nanoseconds - if it's unknown,
29 * CPUFREQ_ETERNAL shall be used.
32 #define CPUFREQ_ETERNAL (-1)
33 #define CPUFREQ_NAME_LEN 16
34 /* Print length for names. Extra 1 space for accomodating '\n' in prints */
35 #define CPUFREQ_NAME_PLEN (CPUFREQ_NAME_LEN + 1)
37 struct cpufreq_governor;
39 struct cpufreq_freqs {
40 unsigned int cpu; /* cpu nr */
43 u8 flags; /* flags of cpufreq_driver, see below. */
46 struct cpufreq_cpuinfo {
47 unsigned int max_freq;
48 unsigned int min_freq;
50 /* in 10^(-9) s = nanoseconds */
51 unsigned int transition_latency;
54 struct cpufreq_user_policy {
55 unsigned int min; /* in kHz */
56 unsigned int max; /* in kHz */
59 struct cpufreq_policy {
60 /* CPUs sharing clock, require sw coordination */
61 cpumask_var_t cpus; /* Online CPUs only */
62 cpumask_var_t related_cpus; /* Online + Offline CPUs */
63 cpumask_var_t real_cpus; /* Related and present */
65 unsigned int shared_type; /* ACPI: ANY or ALL affected CPUs
67 unsigned int cpu; /* cpu managing this policy, must be online */
70 struct cpufreq_cpuinfo cpuinfo;/* see above */
72 unsigned int min; /* in kHz */
73 unsigned int max; /* in kHz */
74 unsigned int cur; /* in kHz, only needed if cpufreq
75 * governors are used */
76 unsigned int restore_freq; /* = policy->cur before transition */
77 unsigned int suspend_freq; /* freq to set during suspend */
79 unsigned int policy; /* see above */
80 unsigned int last_policy; /* policy before unplug */
81 struct cpufreq_governor *governor; /* see below */
83 char last_governor[CPUFREQ_NAME_LEN]; /* last governor used */
85 struct work_struct update; /* if update_policy() needs to be
86 * called, but you're in IRQ context */
88 struct cpufreq_user_policy user_policy;
89 struct cpufreq_frequency_table *freq_table;
91 struct list_head policy_list;
93 struct completion kobj_unregister;
96 * The rules for this semaphore:
97 * - Any routine that wants to read from the policy structure will
98 * do a down_read on this semaphore.
99 * - Any routine that will write to the policy structure and/or may take away
100 * the policy altogether (eg. CPU hotplug), will hold this lock in write
101 * mode before doing so.
103 struct rw_semaphore rwsem;
107 * - fast_switch_possible should be set by the driver if it can
108 * guarantee that frequency can be changed on any CPU sharing the
109 * policy and that the change will affect all of the policy CPUs then.
110 * - fast_switch_enabled is to be set by governors that support fast
111 * freqnency switching with the help of cpufreq_enable_fast_switch().
113 bool fast_switch_possible;
114 bool fast_switch_enabled;
116 /* Synchronization for frequency transitions */
117 bool transition_ongoing; /* Tracks transition status */
118 spinlock_t transition_lock;
119 wait_queue_head_t transition_wait;
120 struct task_struct *transition_task; /* Task which is doing the transition */
123 struct cpufreq_stats *stats;
125 /* For cpufreq driver's internal use */
130 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
131 #define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */
132 #define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */
133 #define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/
135 #ifdef CONFIG_CPU_FREQ
136 struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu);
137 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
138 void cpufreq_cpu_put(struct cpufreq_policy *policy);
140 static inline struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu)
144 static inline struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
148 static inline void cpufreq_cpu_put(struct cpufreq_policy *policy) { }
151 static inline bool policy_is_shared(struct cpufreq_policy *policy)
153 return cpumask_weight(policy->cpus) > 1;
156 /* /sys/devices/system/cpu/cpufreq: entry point for global variables */
157 extern struct kobject *cpufreq_global_kobject;
159 #ifdef CONFIG_CPU_FREQ
160 unsigned int cpufreq_get(unsigned int cpu);
161 unsigned int cpufreq_quick_get(unsigned int cpu);
162 unsigned int cpufreq_quick_get_max(unsigned int cpu);
163 void disable_cpufreq(void);
165 u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy);
166 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
167 int cpufreq_update_policy(unsigned int cpu);
168 bool have_governor_per_policy(void);
169 struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy);
170 void cpufreq_enable_fast_switch(struct cpufreq_policy *policy);
171 void cpufreq_disable_fast_switch(struct cpufreq_policy *policy);
173 static inline unsigned int cpufreq_get(unsigned int cpu)
177 static inline unsigned int cpufreq_quick_get(unsigned int cpu)
181 static inline unsigned int cpufreq_quick_get_max(unsigned int cpu)
185 static inline void disable_cpufreq(void) { }
188 /*********************************************************************
189 * CPUFREQ DRIVER INTERFACE *
190 *********************************************************************/
192 #define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */
193 #define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */
194 #define CPUFREQ_RELATION_C 2 /* closest frequency to target */
197 struct attribute attr;
198 ssize_t (*show)(struct cpufreq_policy *, char *);
199 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
202 #define cpufreq_freq_attr_ro(_name) \
203 static struct freq_attr _name = \
204 __ATTR(_name, 0444, show_##_name, NULL)
206 #define cpufreq_freq_attr_ro_perm(_name, _perm) \
207 static struct freq_attr _name = \
208 __ATTR(_name, _perm, show_##_name, NULL)
210 #define cpufreq_freq_attr_rw(_name) \
211 static struct freq_attr _name = \
212 __ATTR(_name, 0644, show_##_name, store_##_name)
215 struct attribute attr;
216 ssize_t (*show)(struct kobject *kobj,
217 struct attribute *attr, char *buf);
218 ssize_t (*store)(struct kobject *a, struct attribute *b,
219 const char *c, size_t count);
222 #define define_one_global_ro(_name) \
223 static struct global_attr _name = \
224 __ATTR(_name, 0444, show_##_name, NULL)
226 #define define_one_global_rw(_name) \
227 static struct global_attr _name = \
228 __ATTR(_name, 0644, show_##_name, store_##_name)
231 struct cpufreq_driver {
232 char name[CPUFREQ_NAME_LEN];
236 /* needed by all drivers */
237 int (*init)(struct cpufreq_policy *policy);
238 int (*verify)(struct cpufreq_policy *policy);
240 /* define one out of two */
241 int (*setpolicy)(struct cpufreq_policy *policy);
244 * On failure, should always restore frequency to policy->restore_freq
247 int (*target)(struct cpufreq_policy *policy,
248 unsigned int target_freq,
249 unsigned int relation); /* Deprecated */
250 int (*target_index)(struct cpufreq_policy *policy,
252 unsigned int (*fast_switch)(struct cpufreq_policy *policy,
253 unsigned int target_freq);
255 * Only for drivers with target_index() and CPUFREQ_ASYNC_NOTIFICATION
258 * get_intermediate should return a stable intermediate frequency
259 * platform wants to switch to and target_intermediate() should set CPU
260 * to to that frequency, before jumping to the frequency corresponding
261 * to 'index'. Core will take care of sending notifications and driver
262 * doesn't have to handle them in target_intermediate() or
265 * Drivers can return '0' from get_intermediate() in case they don't
266 * wish to switch to intermediate frequency for some target frequency.
267 * In that case core will directly call ->target_index().
269 unsigned int (*get_intermediate)(struct cpufreq_policy *policy,
271 int (*target_intermediate)(struct cpufreq_policy *policy,
274 /* should be defined, if possible */
275 unsigned int (*get)(unsigned int cpu);
278 int (*bios_limit)(int cpu, unsigned int *limit);
280 int (*exit)(struct cpufreq_policy *policy);
281 void (*stop_cpu)(struct cpufreq_policy *policy);
282 int (*suspend)(struct cpufreq_policy *policy);
283 int (*resume)(struct cpufreq_policy *policy);
285 /* Will be called after the driver is fully initialized */
286 void (*ready)(struct cpufreq_policy *policy);
288 struct freq_attr **attr;
290 /* platform specific boost support code */
292 int (*set_boost)(int state);
296 #define CPUFREQ_STICKY (1 << 0) /* driver isn't removed even if
297 all ->init() calls failed */
298 #define CPUFREQ_CONST_LOOPS (1 << 1) /* loops_per_jiffy or other
299 kernel "constants" aren't
300 affected by frequency
302 #define CPUFREQ_PM_NO_WARN (1 << 2) /* don't warn on suspend/resume
306 * This should be set by platforms having multiple clock-domains, i.e.
307 * supporting multiple policies. With this sysfs directories of governor would
308 * be created in cpu/cpu<num>/cpufreq/ directory and so they can use the same
309 * governor with different tunables for different clusters.
311 #define CPUFREQ_HAVE_GOVERNOR_PER_POLICY (1 << 3)
314 * Driver will do POSTCHANGE notifications from outside of their ->target()
315 * routine and so must set cpufreq_driver->flags with this flag, so that core
316 * can handle them specially.
318 #define CPUFREQ_ASYNC_NOTIFICATION (1 << 4)
321 * Set by drivers which want cpufreq core to check if CPU is running at a
322 * frequency present in freq-table exposed by the driver. For these drivers if
323 * CPU is found running at an out of table freq, we will try to set it to a freq
324 * from the table. And if that fails, we will stop further boot process by
325 * issuing a BUG_ON().
327 #define CPUFREQ_NEED_INITIAL_FREQ_CHECK (1 << 5)
329 int cpufreq_register_driver(struct cpufreq_driver *driver_data);
330 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
332 const char *cpufreq_get_current_driver(void);
333 void *cpufreq_get_driver_data(void);
335 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy,
336 unsigned int min, unsigned int max)
338 if (policy->min < min)
340 if (policy->max < min)
342 if (policy->min > max)
344 if (policy->max > max)
346 if (policy->min > policy->max)
347 policy->min = policy->max;
352 cpufreq_verify_within_cpu_limits(struct cpufreq_policy *policy)
354 cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
355 policy->cpuinfo.max_freq);
358 #ifdef CONFIG_CPU_FREQ
359 void cpufreq_suspend(void);
360 void cpufreq_resume(void);
361 int cpufreq_generic_suspend(struct cpufreq_policy *policy);
363 static inline void cpufreq_suspend(void) {}
364 static inline void cpufreq_resume(void) {}
367 /*********************************************************************
368 * CPUFREQ NOTIFIER INTERFACE *
369 *********************************************************************/
371 #define CPUFREQ_TRANSITION_NOTIFIER (0)
372 #define CPUFREQ_POLICY_NOTIFIER (1)
374 /* Transition notifiers */
375 #define CPUFREQ_PRECHANGE (0)
376 #define CPUFREQ_POSTCHANGE (1)
378 /* Policy Notifiers */
379 #define CPUFREQ_ADJUST (0)
380 #define CPUFREQ_NOTIFY (1)
381 #define CPUFREQ_START (2)
382 #define CPUFREQ_CREATE_POLICY (3)
383 #define CPUFREQ_REMOVE_POLICY (4)
385 #ifdef CONFIG_CPU_FREQ
386 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
387 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
389 void cpufreq_freq_transition_begin(struct cpufreq_policy *policy,
390 struct cpufreq_freqs *freqs);
391 void cpufreq_freq_transition_end(struct cpufreq_policy *policy,
392 struct cpufreq_freqs *freqs, int transition_failed);
394 #else /* CONFIG_CPU_FREQ */
395 static inline int cpufreq_register_notifier(struct notifier_block *nb,
400 static inline int cpufreq_unregister_notifier(struct notifier_block *nb,
405 #endif /* !CONFIG_CPU_FREQ */
408 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch
415 * new = old * mult / div
417 static inline unsigned long cpufreq_scale(unsigned long old, u_int div,
420 #if BITS_PER_LONG == 32
421 u64 result = ((u64) old) * ((u64) mult);
423 return (unsigned long) result;
425 #elif BITS_PER_LONG == 64
426 unsigned long result = old * ((u64) mult);
432 /*********************************************************************
433 * CPUFREQ GOVERNORS *
434 *********************************************************************/
437 * If (cpufreq_driver->target) exists, the ->governor decides what frequency
438 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
439 * two generic policies are available:
441 #define CPUFREQ_POLICY_POWERSAVE (1)
442 #define CPUFREQ_POLICY_PERFORMANCE (2)
445 * The polling frequency depends on the capability of the processor. Default
446 * polling frequency is 1000 times the transition latency of the processor. The
447 * ondemand governor will work on any processor with transition latency <= 10ms,
448 * using appropriate sampling rate.
450 * For CPUs with transition latency > 10ms (mostly drivers with CPUFREQ_ETERNAL)
451 * the ondemand governor will not work. All times here are in us (microseconds).
453 #define MIN_SAMPLING_RATE_RATIO (2)
454 #define LATENCY_MULTIPLIER (1000)
455 #define MIN_LATENCY_MULTIPLIER (20)
456 #define TRANSITION_LATENCY_LIMIT (10 * 1000 * 1000)
458 /* Governor Events */
459 #define CPUFREQ_GOV_START 1
460 #define CPUFREQ_GOV_STOP 2
461 #define CPUFREQ_GOV_LIMITS 3
462 #define CPUFREQ_GOV_POLICY_INIT 4
463 #define CPUFREQ_GOV_POLICY_EXIT 5
465 struct cpufreq_governor {
466 char name[CPUFREQ_NAME_LEN];
468 int (*governor) (struct cpufreq_policy *policy,
470 ssize_t (*show_setspeed) (struct cpufreq_policy *policy,
472 int (*store_setspeed) (struct cpufreq_policy *policy,
474 unsigned int max_transition_latency; /* HW must be able to switch to
475 next freq faster than this value in nano secs or we
476 will fallback to performance governor */
477 struct list_head governor_list;
478 struct module *owner;
481 /* Pass a target to the cpufreq driver */
482 unsigned int cpufreq_driver_fast_switch(struct cpufreq_policy *policy,
483 unsigned int target_freq);
484 int cpufreq_driver_target(struct cpufreq_policy *policy,
485 unsigned int target_freq,
486 unsigned int relation);
487 int __cpufreq_driver_target(struct cpufreq_policy *policy,
488 unsigned int target_freq,
489 unsigned int relation);
490 int cpufreq_register_governor(struct cpufreq_governor *governor);
491 void cpufreq_unregister_governor(struct cpufreq_governor *governor);
493 struct cpufreq_governor *cpufreq_default_governor(void);
494 struct cpufreq_governor *cpufreq_fallback_governor(void);
496 /* Governor attribute set */
497 struct gov_attr_set {
499 struct list_head policy_list;
500 struct mutex update_lock;
504 /* sysfs ops for cpufreq governors */
505 extern const struct sysfs_ops governor_sysfs_ops;
507 void gov_attr_set_init(struct gov_attr_set *attr_set, struct list_head *list_node);
508 void gov_attr_set_get(struct gov_attr_set *attr_set, struct list_head *list_node);
509 unsigned int gov_attr_set_put(struct gov_attr_set *attr_set, struct list_head *list_node);
511 /* Governor sysfs attribute */
512 struct governor_attr {
513 struct attribute attr;
514 ssize_t (*show)(struct gov_attr_set *attr_set, char *buf);
515 ssize_t (*store)(struct gov_attr_set *attr_set, const char *buf,
519 /*********************************************************************
520 * FREQUENCY TABLE HELPERS *
521 *********************************************************************/
523 /* Special Values of .frequency field */
524 #define CPUFREQ_ENTRY_INVALID ~0u
525 #define CPUFREQ_TABLE_END ~1u
526 /* Special Values of .flags field */
527 #define CPUFREQ_BOOST_FREQ (1 << 0)
529 struct cpufreq_frequency_table {
531 unsigned int driver_data; /* driver specific data, not used by core */
532 unsigned int frequency; /* kHz - doesn't need to be in ascending
536 #if defined(CONFIG_CPU_FREQ) && defined(CONFIG_PM_OPP)
537 int dev_pm_opp_init_cpufreq_table(struct device *dev,
538 struct cpufreq_frequency_table **table);
539 void dev_pm_opp_free_cpufreq_table(struct device *dev,
540 struct cpufreq_frequency_table **table);
542 static inline int dev_pm_opp_init_cpufreq_table(struct device *dev,
543 struct cpufreq_frequency_table
549 static inline void dev_pm_opp_free_cpufreq_table(struct device *dev,
550 struct cpufreq_frequency_table
557 * cpufreq_for_each_entry - iterate over a cpufreq_frequency_table
558 * @pos: the cpufreq_frequency_table * to use as a loop cursor.
559 * @table: the cpufreq_frequency_table * to iterate over.
562 #define cpufreq_for_each_entry(pos, table) \
563 for (pos = table; pos->frequency != CPUFREQ_TABLE_END; pos++)
566 * cpufreq_for_each_valid_entry - iterate over a cpufreq_frequency_table
567 * excluding CPUFREQ_ENTRY_INVALID frequencies.
568 * @pos: the cpufreq_frequency_table * to use as a loop cursor.
569 * @table: the cpufreq_frequency_table * to iterate over.
572 #define cpufreq_for_each_valid_entry(pos, table) \
573 for (pos = table; pos->frequency != CPUFREQ_TABLE_END; pos++) \
574 if (pos->frequency == CPUFREQ_ENTRY_INVALID) \
578 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
579 struct cpufreq_frequency_table *table);
581 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
582 struct cpufreq_frequency_table *table);
583 int cpufreq_generic_frequency_table_verify(struct cpufreq_policy *policy);
585 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
586 struct cpufreq_frequency_table *table,
587 unsigned int target_freq,
588 unsigned int relation,
589 unsigned int *index);
590 int cpufreq_frequency_table_get_index(struct cpufreq_policy *policy,
593 ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf);
595 #ifdef CONFIG_CPU_FREQ
596 int cpufreq_boost_trigger_state(int state);
597 int cpufreq_boost_enabled(void);
598 int cpufreq_enable_boost_support(void);
599 bool policy_has_boost_freq(struct cpufreq_policy *policy);
601 static inline int cpufreq_boost_trigger_state(int state)
605 static inline int cpufreq_boost_enabled(void)
610 static inline int cpufreq_enable_boost_support(void)
615 static inline bool policy_has_boost_freq(struct cpufreq_policy *policy)
620 /* the following funtion is for cpufreq core use only */
621 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
623 /* the following are really really optional */
624 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
625 extern struct freq_attr cpufreq_freq_attr_scaling_boost_freqs;
626 extern struct freq_attr *cpufreq_generic_attr[];
627 int cpufreq_table_validate_and_show(struct cpufreq_policy *policy,
628 struct cpufreq_frequency_table *table);
630 unsigned int cpufreq_generic_get(unsigned int cpu);
631 int cpufreq_generic_init(struct cpufreq_policy *policy,
632 struct cpufreq_frequency_table *table,
633 unsigned int transition_latency);
634 #endif /* _LINUX_CPUFREQ_H */